Ever since Oculus co-founder Palmer Luckey revealed that the first consumer Oculus Rift headset would launch at $600, many industry watchers have been arguing that the high price of entry was keeping virtual reality from becoming a truly revolutionary mass-market technology. Though prices for VR headsets and compatible hardware have come down quite a bit since then, sales and usage stats are still struggling to climb out of the doldrums when compared with other tech products.

Now Luckey, who left Oculus in early 2017, argues in a recent blog post that there is no price low enough to convince a critical mass of people to regularly engage with existing VR headsets:

No existing or imminent VR hardware is good enough to go truly mainstream, even at a price of $0.00. You could give a Rift+PC to every single person in the developed world for free, and the vast majority would cease to use it in a matter of weeks or months.

I know this from seeing the results of large scale real-world market testing, not just my own imagination—hardcore gamers and technology enthusiasts are entranced by the VR of today, as am I, but stickiness drops off steeply outside of that core demographic. Free is still not cheap enough for most people, because cost is not what holds them back actively or passively.

Luckey goes on to estimate that current VR technology could attract an absolute ceiling of 50 million active users worldwide—and that number only with significant industry effort. That’s a far cry from the 1 billion users Facebook CEO Mark Zuckerberg cites as his long-term goal for VR adoption.

Rather than price, Luckey says it’s “quality of experience” that’s holding VR back, and it’s not hard to see what he means. As cool as current VR headsets are, they’re still saddled with sweat-inducing bulk, limited resolution, 3D vergence issues, artificial hand-tracking interfaces, and more. While current technology can fix problems like getting tangled up in wires (for a price), those other VR quality-of-life issues will persist, pending technological breakthroughs, as Oculus’ Michael Abrash laid out in a talk at Oculus Connect last month.

Software is the other side of the equation. While there are plenty of great games and experiences available in VR these days, there aren’t too many that could be described as “killer apps” that would drive the average consumer to feel they absolutely need to integrate a headset into their everyday lives. This is especially true for non-gamers—a recent survey by Civic Science found that 77 percent of people who want to buy a VR headset play video games. That same survey finds a full 50 percent of respondents are just “not interested” in VR technology, adding weight to Luckey’s point.

All that said, Luckey isn’t worried that these problems will always hold back what he still calls a “reasonable candidate for most important technology of the century.” Even assuming “moderate technological advancement compounded over decades,” Luckey says improvements in hardware, content, and interface will eventually lead to VR’s “inevitable dominance as the final platform.” He urges those in the space to work at making those improvements more quickly, rather than spending money on “forced marketing to segments of the world that are not yet ready to embrace VR.”